A dangerous truth is emerging from Ukraine. Kyiv is slowly starting to lose the war against Russia because it is running short of ammunition, in large part because promises made by the EU and the USA are not being honoured. Concurrently, Russia has moved to a wartime economic footing, with 40 per cent of government spending now on the military. The result has seen Ukraine start to lose territory.

In the east of the country, where I visited last week, talk is turning to which town will fall next. Soldiers are angry that they are dying because they do not have the ammunition – and specifically artillery shells – to return fire on Russian positions. If this continues, disaster awaits Ukraine and a great danger awaits Europe. The facts are as below.

Ukraine is not getting the shells it was promised. EU states pledged to deliver one million shells in 2023. In reality, they delivered barely a third. The hold-up in Congress of a major aid package from the US is also restricting the supply of shells. While the UK has been responsive and shown strong leadership, we haven’t always given as much as we think we have given, considering the scale of the violence. Ukraine has used some four million shells since the start of the war, Russia many times that.

Ukraine still needs enough mass to hold its lines

Next, the barrels of at least 300 western 155mm artillery pieces that Ukraine is using will need replacing. These western barrels are becoming more important, and their loss more keenly felt, as global ammunition stocks for Ukraine’s Soviet-era 152mm weaponry dries up. Finally, on F-16 fighter jets, Ukraine will have a modest number of aircraft, but the two Nato states that are training pilots are training only a small number of pilots this year, so while the planes will be some deterrent, the numbers of available pilots will restrict their use. Ukraine’s air defence missile stocks are also running low at the same time as Russia is engaging successfully in the drone war. Lancet kamikaze drones and Orlan reconnaissance drones are hurting Ukrainian front line positions.

It’s important to remind ourselves of the style of warfare Russia is using in this stage of the conflict. The Kremlin wanted a swift victory in February 2022. It failed. Since then, it has focused on a war of attrition, to wear down Ukraine by mass: mass infantry, mass artillery barrages. Ukrainian towns and cities are simply flattened – leaving them uninhabitable for years, possibly decades. This form of warfare takes very little account of human life, but that is not the point. Putin will happily shed 500,000 Russian lives for half that number of Ukrainians because he knows that it will result in Russian victory.

In the recent capture of Avdiivka, a small but usefully situated town on the front line since 2014, the Russians were rumoured to have 18,000 to 20,000 killed and wounded. Even if Ukraine’s dead and injured were only a quarter, 4,000 volunteers matter more to Kyiv than 18,000 men from Russian provinces forgotten to President Vladimir Putin.

Ukraine, however, is learning how to counter Russian mass with technology. It is producing drones for land, sea and air. In a small factory I visited this week, a few of the country’s army of geeks were at work late at night building land drones, small four-wheel drive machines little more than the size of lawn mowers that can carry a mounted machine gun, with the human operator 50 or 100 metres away. Ukraine needs thousands of these along a front line that stretches some 600 miles. But even with technology, Ukraine still needs enough mass to hold its lines, and promised supplies from Nato states are not materialising, making the artillery war one-sided. The shell crisis is so acute that supplies will go off a cliff within three months unless more are found.

Arming Ukraine remains a matter of self-interest and principle. We signed a treaty to guarantee Ukraine’s territorial integrity in 1994 in exchange for Ukraine abandoning its nuclear weapons. If we don’t honour this promise, what’s to stop Putin thinking we won’t honour the promise to protect Nato frontline states? Our world is becoming more dangerous, too. If the allies of free states are destroyed by authoritarian powers, it will confirm the precedent started in Afghanistan – the western alliance has no stomach for long-term commitment.

During the Cold War, we played a long game to contain Russia. We need to do so again. The least bad option remains this: arm Ukraine or face a much greater risk of a wider conflict in Eastern Europe. Right now, Ukrainians are dying for want of the kit Nato states promised.